Grinding machine abrasive element



Feb. 6', 1934. J. suNNEN GRINDING MACHINE ABRASIVE ELEIINT Filed 001'.. 29. 1932 Patented Feb. 6, 1934 UNITED STATES GRINDING MACHINE ABRASIVE ELEMENT Joseph Sunnen, Kirkwood, Mo.

Application October 29,

9 Claims.

My invention has relation to improvements in grinding or abrading elements for grinding or honing machines of the type ilustrated and described in my co-pending application, Serial No. 233,788, led November 17, 1927, and it consists in the novel features of construction more fully set forth in the specification and pointed out in the claims.

The principal object of the present invention is to provide a grinding element for a grinding machine of the type described in the above referred to application, the abrasive stick of which is so constructed that practically the entire stick may be used, thus prolonging the life of the abrasive elements. This advantage, as well as others inherent in the invention, will be better apparent from a detailed description thereof in connection with the accompanying drawing, in which:

Figure l is a side elevation of a grinding machine equipped with my improved grinding elements and parts of the carrier for said elements being broken away; Fig. 2 is a horizontal crosssection taken on the line 2-2 of Fig. l; Fig. 3 is a face view of my improved grinding element; Fig. 4 is a side elevation thereof; and Fig. 5 is a cross-sectional detail taken on the line 5 5 of Fig. 3.

Grinding machines of the type described in said application are wellknownintheartandas shown in the drawing comprise a holder 1 supported from a shaft 2 by a universal joint including the fork 3, collar 4 and studs 5, 5. The holder 1 is provided with a longitudinally disposed axial bore 6 in which is mounted an elongated pinion 7 which cooperatively engages a pair of rack bars 8, 8 carrying on their outer ends a grinding element 9. As described in the aforesaid application, there are two such grinding elements 9, 9 and also two guide elements 10, 10 likewise carried on the outer ends of rack bars 11, 11. The rack bars 8, 8 for the grinding elements are slidably mounted in transverse bores 12, 12, and the rack bars 11, 11 for the guide elements are slidably mounted in transverse bores 13, 13 disposed at right angles to the bores 12, 12 (Fig. 2). The constructional details just described are common to grinders of this type and of themselves form no part of the present invention which is restricted to the construction of the grinding elements per se illustrated in Figs. 3 to 5 inclusive.

The grinding elements as heretofore constructed comprise a channel-shaped holder for the abrasive stone or stick, and when the stone has been PATENT OFFICE 1932. Serial No. 640,272

worn down to a thickness so that it is flush with the top edges of the sides of the channel it is no longer serviceable as the channel sides will then encounter the wall of the cylinder being ground. When these stones have been worn to this extent there is still a good deal of serviceable material in the stone which cannot be used because of the said obstruction caused by the sides of the channel. Mechanics in some instances rell these channels by inserting new abrasive stones therein but such relled elements are often unsatisfactory because of the inferiority of the abrasive used.

It is the object of the present invention to provide a grinding element comprising an abrasive stone and holder therefor, said holder being so constructed as to allow practically the entire stone to be used in grinding operations, thereby overcoming the waste inherent in the old construction as above described.

Referring now to Figs. 3 to 5 inclusive, 14 represents the holder for the stone 15, said holder comprising a base 16 and a uted side wall 17 disposed on the following side of the holder with respect to the direction of rotation thereof when the grinder'is in action. It will be noted that the adjacent iiutes 18, 18 extending along the length of the wall 17 are oppositely disposed. that is, flutes 18 being open outwardly while the flutes 18 open inwardly, said flutes having connecting walls 19 in common between which vextend the walls 20, 20. The walls 20, 20 are perpendicular to the inclined supporting surface 22 of the holder 14, and the stone l5 is disposed on said surface 22 in abutting relation with the walls 20 of the flutes 18. Theabrasive stone 15 is caused to adhere to the surface 22 and outer surfaces of walls 20 by means of a cement grouting which is applied to said surface 22 and walls 20 and allowed to flow into the flutes 18', thereby causing adhesion between the stone and the inner surfaces of wall 20 so that the stone is firmly cemented in place in the holder 14. By imparting to the backing 17 the iiuted or corrugated shape as shown the necessary strength is obtained for backing up the stone l5 in its grinding operations with a minimum amount of metal. In fact, if the same amount of strength were to be imparted to a plain wall of uniform thickness considerably more cross-sectional area would be required. The advantage of the reduction in the amount of metal will be readily apparent when it is considered that I propose that the backing 17 shall be worn down together with the abrasive stone 15 after the latter has been reduced in vbacking 17, should be riable and thickness so that its abrading surface a.' shall lie in the same plane as the free edge oi the backing 17 (as shown by the dottedv line in Fig. 5).

In order that the backing may be worn off by contact with the cylinder wall after the grinding stones 15 have been reduced, as above described, and at the same time will not score the cylinder wall or interfere in any manner with the grinding thereof, I form the entire holder 14 of a metal that is softer in the scale of hardness than the cast iron or the cylinder and they will at the `same time be pulverzed by contact with the cylinder without spreading or cylinder wall. In other smearing over the words, the metal of which the holder 14 is composed, and preferably the wear by attrition in Contact with the'cylinder wall without scoring said wall or filling the pores thereof. I have found that die cast metal containing the proper proportions of Zinc, aluminum and copper will serve the purpose, although I do not wish to be restricted to this particular Vmetal as I desire to avail myself of any metal or alloy that has the properties herein specified. A specirlc composition of metal that serves the purposewell is one containing 93% zinc, 5% aluminum and 2% copper. l

It will be observed that the inclination of the surface 22 tilts the stone 15 slightly forwardly with respect to the direction of the rotation oi the'grinder (Fig. 2). This avoids the necessity for shaping the surface c of the stone. l5 to adapt the same toy have a Wide contact with the suriace of the cylinder, which would otherwise be necessary owing to the fact that the racks 8, 8 are to one side of the rotation axis or machine. The inclination of the surface 22 just Vsuihcient so that said surface may be perpendicular to a radial line .t drawn from the rotation of the machine through the center of the stone (Fig. 2)

The holder i4 may be carried on the ends of the racks 8, 8 in any desirable manner-although I prefer that the extremities 8 o the racks be reduced in diameuer and passed through counter-sunk openings o, o in the base 16 of the holder after which the end ci each reduced extremity 8 is upset into the countersunk portion of lthe opening to produce a substantial riveted connection.

Having described my invention, I claim:

1. An abrasive element for cylinder grinding machines comprising supporting members, a holder carried thereby, and a stone fixed in said holder, said holder having a suitable backing for the stone, and said backing consisting of a metallic alloy havinga Zinc base and con-Y taining aluminum and copper.

cylinder.

3. An abrasive element for cylinder grinding machines comprising supporting members, a holder carried thereby, and a stone fixed in said holder, said holder having a suitable backing.

' for the stone, said backing comprising a series o1 juxtaposed ribs extending from end. to end of the stone.-

ll. An abrasive element for cylinder grinding machines comprising supporting members, a holder carried thereby, and a stone fixed in said holder, said holder having a suitable backing for the stone, said backing comprising a series of juxtaposed ribs formed integrally with the holder.

5. .An abrasive element Jfor cylinder grinding machines comprising supporting members, a holder carried thereby, and an abrasive stone fixed in the holder, said holder comprising a base member and a luted abutment member contiguous to one side of the base member, said stone being cemented to the base member and abutment member. I

S. An abrasive element for cylinder grinding machines comprising supporting members, a holder carried thereby, and an abrasive stone iixed in the holder, said holder comprising a base member and an abutment member contiguous to one side of the base member, said abutment member having a series of pockets formed on its inner surface, and a cement grouting between the stone and the base and the backing, said gronting extending into the pockets aforesaid.

'1. An abrasive element for cylinder grinding machines comprising supporting members, a holder carried thereby, and a stone fixed in said holder, said holder having a suitable backing for the stone, said backing comprising a luted wall.

8. .lin abrasive element for cylinder grinding machines comprising supporting members, a metallic holder carried thereby, and an abrasive stone fixed in said holder, said holder having a corrugated abutment Wall adjacent to one sido ci the stone.

9. [in abrasive element for cylinder grinding machines comprising supporting members, a holder carried thereby, and av stone cemented in said holder, said holder consisting of a metallic alloy containing Zinc and aluminum.

JOSEPH SUNNEN. 

